在OpenCV中利用鼠标绘制矩形和截取图像的矩形区域

这是两个相关的程序，前者是后者的基础。实际上前一个程序也是在前面博文的基础上做的修改，请参考《在OpenCV中利用鼠标绘制直线》 。下面贴出代码。

程序之一，在OpenCV中利用鼠标绘制矩形

#include <cv.h>
#include <highgui.h>
#include <stdio.h>
#pragma comment( lib, "cv.lib" )
#pragma comment( lib, "cxcore.lib" )
#pragma comment( lib, "highgui.lib" )
IplImage* src = 0;
IplImage* dst = 0;
void on_mouse( int event, int x, int y, int flags, void* ustc)
{
    static CvPoint pre_pt = {-1,-1};
    static CvPoint cur_pt = {-1,-1};
    CvFont font;
    cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);
    char temp[16];

    if( event == CV_EVENT_LBUTTONDOWN )
    {
        cvCopy(dst,src);
        sprintf(temp,"(%d,%d)",x,y);
        pre_pt = cvPoint(x,y);
        cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255));
        cvCircle( src, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
        cvShowImage( "src", src );
        cvCopy(src,dst);
    }
    else if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))
    {
        cvCopy(dst,src);
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvShowImage( "src", src );
    }
    else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
    {
        cvCopy(dst,src);
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvRectangle(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
        cvShowImage( "src", src );
    }
    else if( event == CV_EVENT_LBUTTONUP )
    {
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvCircle( src, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
        cvRectangle( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
        cvShowImage( "src", src );
        cvCopy(src,dst);
    }
}
int main()
{
    src=cvLoadImage("lena.jpg",1);
    dst=cvCloneImage(src);
    cvNamedWindow("src",1);
    cvSetMouseCallback( "src", on_mouse, 0 );

    cvShowImage("src",src);
    cvWaitKey(0);
    cvDestroyAllWindows();
    cvReleaseImage(&src);
    cvReleaseImage(&dst);
    return 0;
}

效果图如下

 

程序之二，在OpenCV中利用鼠标绘制矩形并截取该矩形区域的图像

#include <cv.h>
#include <highgui.h>
#include <stdio.h>
#pragma comment( lib, "cv.lib" )
#pragma comment( lib, "cxcore.lib" )
#pragma comment( lib, "highgui.lib" )
IplImage* org = 0;
IplImage* img = 0;
IplImage* tmp = 0;
IplImage* dst = 0;
void on_mouse( int event, int x, int y, int flags, void* ustc)
{
    static CvPoint pre_pt = {-1,-1};
    static CvPoint cur_pt = {-1,-1};
    CvFont font;
    cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);
    char temp[16];

    if( event == CV_EVENT_LBUTTONDOWN )
    {
        cvCopy(org,img);
        sprintf(temp,"(%d,%d)",x,y);
        pre_pt = cvPoint(x,y);
        cvPutText(img,temp, pre_pt, &font, cvScalar(0,0, 0, 255));
        cvCircle( img, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
        cvShowImage( "img", img );
        cvCopy(img,tmp);
    }
    else if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))
    {
        cvCopy(tmp,img);
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(img,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvShowImage( "img", img );
    }
    else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
    {
        cvCopy(tmp,img);
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(img,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvRectangle(img, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
        cvShowImage( "img", img );
    }
    else if( event == CV_EVENT_LBUTTONUP )
    {
        cvCopy(tmp,img);
        sprintf(temp,"(%d,%d)",x,y);
        cur_pt = cvPoint(x,y);
        cvPutText(img,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
        cvCircle( img, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
        cvRectangle( img, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
        cvShowImage( "img", img );
        cvCopy(img,tmp);
        int width=abs(pre_pt.x-cur_pt.x);
        int height=abs(pre_pt.y-cur_pt.y);
        if(width==0 || height==0)
        {
            cvDestroyWindow("dst");
            return;
        }
        dst=cvCreateImage(cvSize(width,height),org->depth,org->nChannels);
        CvRect rect;
        if(pre_pt.x<cur_pt.x && pre_pt.y<cur_pt.y)
        {
            rect=cvRect(pre_pt.x,pre_pt.y,width,height);
        }
        else if(pre_pt.x>cur_pt.x && pre_pt.y<cur_pt.y)
        {
            rect=cvRect(cur_pt.x,pre_pt.y,width,height);
        }
        else if(pre_pt.x>cur_pt.x && pre_pt.y>cur_pt.y)
        {
            rect=cvRect(cur_pt.x,cur_pt.y,width,height);
        }
        else if(pre_pt.x<cur_pt.x && pre_pt.y>cur_pt.y)
        {
            rect=cvRect(pre_pt.x,cur_pt.y,width,height);
        }
        cvSetImageROI(org,rect);
        cvCopy(org,dst);
        cvResetImageROI(org);
        cvDestroyWindow("dst");
        cvNamedWindow("dst",1);
        cvShowImage("dst",dst);
        cvSaveImage("dst.jpg",dst);
    }
}
int main()
{
    org=cvLoadImage("lena.jpg",1);
    img=cvCloneImage(org);
    tmp=cvCloneImage(org);
    cvNamedWindow("img",1);
    cvSetMouseCallback( "img", on_mouse, 0 );

    cvShowImage("img",img);
    cvWaitKey(0);
    cvDestroyAllWindows();
    cvReleaseImage(&org);
    cvReleaseImage(&img);
    cvReleaseImage(&tmp);
    cvReleaseImage(&dst);
    return 0;
}

 

效果图如下

 

from:http://blog.csdn.net/quarryman/article/details/6435527